1. Technical Field
The embodiments described herein relate to Ultra Wideband (UWB) communication, and more particularly, methods of synchronizing with a first multipath component in an UWB receiver in a multipath channel environment and UWB receivers using the same.
2. Discussion of Related Art
UWB systems can transmit and receive data in a local area without interfering with other systems by transmitting low-power signals at a high data transmission rate using short pulses and a relatively large bandwidth. A large amount of research is aimed at UWB systems applicable to a Wireless Personal Area Network (WPAN) for indoor local area communication at an ultrahigh rate.
For communication systems to operate properly, received signals must be synchronized. A synchronization rate or accuracy is an important measure for evaluating system performance.
The UWB systems are affected by a complex multipath channel. Since the UWB systems use low-power signals, it is difficult to perform synchronization. Accordingly, the synchronization is done using a long preamble. Since UWB systems have a wider search space than conventional communication systems, synchronization is time-consuming.
To address the above problems, research has aimed at shortening synchronization time using many synchronization methods. Synchronization is conventionally defined as aligning phase difference between the phase of a template signal of a receiver and the phases of multipath components of a received signal to within a given range.
As described in I. Ramachandran and S. Roy, “On Acquisition of Wideband Direct-sequence Spread Spectrum Signals,” IEEE Trans Commun, vol. 5, no. 6, pp. 1537-1546, June 2006, a UWB system compares an absolute value of a correlation value between a template signal and a received signal with a threshold, determines that synchronization is accomplished when the absolute value is greater than the threshold, and achieves fast synchronization by applying many search methods.